Correlations of flow harmonics in 2.76A TeV Pb-Pb collisions

Abstract

Using the event-by-event viscous hydrodynamics VISH2+1 with MC-Glauber, MC-KLN, and AMPT initial conditions, we investigate the correlations of flow harmonics, including the symmetric cumulants SC v (m, n), the normalized symmetric cumulants N SC(m, n), and the Pearson correlation coefficients C(v 2 m , v 2 n ) in 2.76A TeV Pb-Pb collisions. We find SC v (m, n) is sensitive to both initial conditions and the specific shear viscosity η/s. A comparison with the recent ALICE data show that our hydrodynamic calculations can qualitatively describe the data of SC v (3, 2) and SC v (4, 2) for various initial conditions, which demonstrate that v2, v4 are correlated and v2, v3 are anti-correlated. Meanwhile, the predicted symmetric cumulants SC v (5, 2), SC v (5, 3), and SC v (4, 3) reveal that v2 and v5, v3 and v5 are correlated, v3 and v4 are anti-correlated in most centrality classes. We also find N SC v (3, 2) and C(v 2 3 , v 2 2 ), which are insensitive to η/s, are mainly determined by corresponding N SC ε (3, 2) and C(ε 2 3 , ε 2 2 ) correlators from the initial state. In contrast, other N SC v (m, n) and C(v 2 m , v 2 n ) correlators are influenced by both initial conditions and η/s, which illustrates the non-linear mode couplings in higher flow harmonics with n ≥ 4.

Search for the chiral magnetic effect in relativistic heavy-ion collisions

“…[70][71][72] Similar to Eq.19,20,21,22, these relations hold by replacing the ψ PP with ψ EP . For example, Figure 21(upper panel) shows R P P ( 2 ) and R P P (B sq ) calculated by a Monte Carlo Glauber model 73,74 for Au+Au, Cu+Cu, Ru+Ru, Zr+Zr collisions at RHIC and Pb+Pb collisions at the LHC. The results are compared to the corresponding ±R P P .…”

Systematic studies of correlations between different order flow harmonics in Pb-Pb collisions at sNN=2.76 TeV

“…The new observables are particularly robust against few-particle nonflow correlations [8] and they provide independent, complementary information to recently analyzed symmetry plane correlators [37]. It was demonstrated that they are sensitive to the temperature dependence of η/s of the expanding medium and therefore simultaneous descriptions of correlations between different order harmonics would constrain both the initial conditions and the medium properties [57,58]. In this article, we have extended the analysis of SC observables to higher order harmonics (up to fifth order) as well as to the measurement of the p T dependence of correlations for the lower order harmonics (v 3 -v 2 and v 4 -v 2 ).…”

“…By tuning transport coefficients and decoupling temperature for a given scenario of initial conditions, it can describe the p T spectra and different flow harmonics at RHIC and the LHC [20,76,82,83] energies. Three different types of initial conditions [58] (MC-Glauber, Monte Carlo Kharzeev-Levin-Nardi (MC-KLN), and AMPT) along with different constant η/s values have been used for our data to model comparisons. Traditionally, the Glauber model constructs the initial entropy density from the wounded nucleon and binary collision density profiles [84].…”

Collective Effects in Nuclear Collisions: Experimental Overview

“…Besides, it was found that although hydrodynamic calculations using EKRT initial condition and various parameterizations could nicely describe measurements of v n , none of the hydrodynamic calculations could quantitatively fit the sizes of S C(3, 2) and S C(4, 2) simultaneously. This study was further extended to correlations between higher order flow coefficients by ALICE [39] and compared to more available theoretical calculations [25], which again suggest S C(m, n) as a tight constraint on theoretical models. Recently, results are also reported in various collision systems, including Pb-Pb, Au-Au, Xe-Xe, p-Pb and pp collisions [40,41].…”

“…In addition to standard studies on flow coefficient for charged and identified particles, other flow observables, for example event-by-event flow fluctuations [14,15], fluctuations (de-correlation) of flow-vector [16][17][18][19][20][21], and the correlations between different order flow-vectors [22][23][24][25][26][27], have also been investigated in great details in relativistic heavy-ion collisions. The comparisons between latest experimental data and recent development of event-by-event hydrodynamical model simulations on various flow observables shed new insight into the the initial conditions and the properties of the create QGP matter in heavy-ion collisions [5].…”